


Irreplaceable

by mylordshesacactus



Category: RWBY
Genre: Emotional Manipulation, F/F, Jealousy, Look Cinder Is Not A Nice Person And Emerald Has Issues Okay, Possessive Behavior
Language: English
Status: Completed
Published: 2016-08-11
Updated: 2016-08-11
Packaged: 2018-08-08 03:46:50
Rating: Teen And Up Audiences
Warnings: No Archive Warnings Apply
Chapters: 1
Words: 4,398
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/7742137
Author URL: https://archiveofourown.org/users/mylordshesacactus/pseuds/mylordshesacactus
Summary: <blockquote class="userstuff">
              <p>Anyone, no matter how rare or devoted, can be replaced.</p><p>Remember that, Emerald.</p>
            </blockquote>





	Irreplaceable

Mercury heaved a dramatic sigh.

For the third time in the past five minutes.

Emerald rolled her eyes and ignored him, tapping her scroll to upgrade a tower.  _ Grimm Border Defense Force III _ \--the irony did not escape her--wasn’t nearly as much fun in single-player mode, but no way was she telling Mercury that. Besides, he wasn’t a good enough strategist as the Grimm and his brute-force approach to tower design made for a really boring match when she was the attacker.

Mercury sighed again.

Patience gone, Emerald snapped her scroll closed.

“Oh, come on!” she protested. “You are  _ not  _ bored. We  _ literally  _ just got out of a fight two hours ago.”

“Exactly,” he said with exaggerated patience. “It’s been two hours since I was in a decent fight!”

She smirked. “Thought you said that fight was too easy.”

“Eh.” Mercury shrugged. “Maybe if he wasn’t too stupid to get his head out of a geyser it might have gotten interesting eventually. It was harder than a playdate with a walking handbag, anyway. You know, once you  _ finally  _ decided to grace me with your generous support.”

“Well if  _ you  _ had quit messing around and let me get a clear shot in--”

“Children,” Cinder said mildly, not looking up from her scroll.

Emerald winced. “Sorry, ma’am.”

She didn’t look angry, at least, as she made a few adjustments to whatever she was working on and slid the scroll closed. She stood, and Emerald reflexively got to her feet as well. Mercury just stretched and crossed his arms behind his head. Emerald didn’t really get annoyed by that anymore, but she still couldn’t imagine being so...insolent, around their mistress. Just because Cinder was dressed like a Haven student didn’t give her any less of a magnetic presence.

As usual, though, Cinder mostly just seemed faintly amused with him. “You both performed well today,” she said. “I was  _ particularly  _ pleased with how you dealt with Adel, Emerald. That speaks well of your ability to allay suspicions in the audience, when the time comes.”

Emerald tried not to preen too obviously. “Oh! Thanks, Cinder. It, uh. It was nothing.”

Cinder smiled faintly. “Hardly. You have a rare gift.”

Oh man. She had to be  _ glowing  _ now, but she couldn’t help it. She tried to fight back a grin as she scratched the back of her head. “No, really. It’s no trouble. I could do that in my sleep.”

“Is that so?” Cinder’s voice was sweet and soft and doing terrible, awful things to Emerald’s insides.

“Definitely!” she babbled, too bright. “Taking candy from a baby. Pulling it off in the final won’t be a problem at all. Ma’am. They’ll see whatever you want. Not even hard.”

Cinder’s smile widened as she reached out, running fingertips along Emerald’s cheek that set her whole body on fire. Figuratively. Probably. She was too distracted to check.

“Well,” she purred, laughter and flame dancing in her eyes. “If it was truly so simple, perhaps the reward I had in mind  _ was  _ a bit excessive.” She tapped Emerald’s lips and turned gracefully toward the door. 

Emerald’s eyes widened.

“W-well,” she said. “It was still pretty impressive…”

Cinder didn’t appear to hear her. “Stay here. I’ll contact you both with further instructions soon.”

“Right?” Emerald continued weakly. “I mean, who else could pull that off? I had to get the...the timing right, and balance the audience perception with the illusion and...everything… _ ” _ She closed her eyes and banged her head back against the wall as the door closed behind Cinder.  _ Me and my big mouth. _

“And with that,” Mercury announced after a long pause, pretending to be reading out of a textbook. It would have been more convincing if his tone was less mocking. “Emerald finally made peace with the sexy schoolgirl kink she didn’t even know she had.”

“I  _ hate  _ you.”

“That was just sad. That hurt to watch, except it was hilarious.”

“Shut up,” she groaned, slipping back to the ground. “Shut up shut up shut up.”

“You need to get laid, Em.”

She glared at him. “Mercury,” she growled. “If you nominate yourself, I  _ swear  _ you will see cockroaches in your food for the rest of your natural life.”

He crossed his arms behind his head again, blatantly getting comfortable against the wall. “You’re missing out and you know it.”

“ _ Ew _ .”

Mercury just closed his eyes and grinned. After glaring suspiciously at him for a few more moments, Emerald pulled out her scroll and started blasting Grimm from her fortified towers with extreme prejudice.

* * *

“You’d better have pants on, Merc,” Emerald called loudly as she shouldered the door open. “Seriously, I was not kidding about the cockroaches!”

Mercury flipped her off when she turned around, but at least he really was wearing pants. Emerald had  _ seen things _ , okay?

“Lady doth protest too much,” he smirked. She ignored him. He was much better company that way.

“Neo left?” she asked after looking around their storage room a few times. You could never quite be sure with that girl. Neo liked to appear out of nowhere, batting her eyelashes and probably plotting to steal your soul or dice your eyeballs or something.

Mercury sighed overdramatically. “I see how it is! You don’t care about me at all. This was all a plot to seduce  _ Neo.” _

“Yeah,” she said flatly. “I like my kidneys  _ inside  _ my body.” She flung a box of takeout noodles and chicken at his face. Much as she’d have loved for him to miss, he snatched it out of the air. Oh, well. There was always next time.

“Aw,” he said, sending her a taunting look that she already knew she was going to fall for. “Is this it? I wanted pizza.”

Plastering her best fake smile across her face, Emerald asked brightly, “Want me to break your  _ other  _ leg?”

He shook his head in despair. “No respect for the hero of the hour,” he muttered around a mouthful of noodles.

Emerald’s eyes narrowed. “Hey, hero,” she snapped.  _ “I _ pulled it off.”

“Sorry,” he drawled.  _ “Who _ was it in the arena again? Oh,  _ right. _ Not you.”

“I--”

“Because you were in a nice cushy seat on the sidelines.”

“You stood there and got punched. I did all the  _ work.” _

Mercury gave a shit-eating grin and took another oversized bite of noodles. “Oh, yeah, sure,” he said. “You did great. The impulse purchase finally comes in handy.”

For a minute, Emerald stopped breathing.

_ “What,” _ she hissed.

“I mean.” Mercury gave a careless shrug, not even looking in her direction. “You just got lucky, right? You were in the right place at the right time and she got curious. It’s not like she, yanno.” He turned a piece of chicken over and tossed it into his mouth, mumbling around it, “Actually  _ wanted  _ you.”

For a moment, red swam in front of her eyes and her mouth filled with the taste of blood.  _ That’s not funny, that’s not _ funny--Mercury was an asshole, but this was  _ different, _ this was personal. Cinder was the only person who’d ever thought Emerald Sustrai was worth anything. And she did. She  _ did.  _ Cinder didn’t do charity, she wouldn’t have raised Emerald up from nothing if she didn’t want her--

Emerald snarled. “You mean like she wanted your  _ dad?” _

“Yup. Went to all that trouble looking for us on purpose.” He swallowed and pointed to himself. “Upgrade.” He gestured to Emerald. “Window shopping. Not complicated.”

“Shut  _ up!”  _

The kick didn’t connect with his face, no matter how much she was  _ burning  _ to make him bleed. She still got a rush of petty satisfaction from knocking the rest of his dinner halfway across the room.

“I wasn’t finished,” he complained.

She bared her teeth at him. “I am.”

Mercury tsked at her back as she stalked toward the door. “Oh, Em,” he said sadly. “Cinder would be  _ very  _ unhappy to hear her favorite errand girl’s been shirking her chores.”

“You sound like Torchwick,” she spit at him.

But she stopped and turned around.

Merc still just looked like he was having fun and she hated him for it. She  _ hated  _ that he was just some punk kid, a dime-a-dozen hired thug who was a little better at killing people than most, someone Cinder hadn’t even known existed until he killed some alcoholic douchebag at the right moment, and he didn’t  _ care. _ It didn’t matter to him what the plan was, or if it even worked, or whether he met Cinder’s standards.

He didn’t care whether Cinder cut him loose or not. He didn’t care about being abandoned. He may have had a shitty life, but Mercury Black had never been  _ nothing. _

He didn’t  _ get  _ to throw that in her face when his part could be played by anyone!

“You know,” he said, kicking back thoughtfully, “I’m a total dick.”

No argument here. “Well at least you’re self-aware,” she muttered.

Naturally, he couldn’t just quit while he was ahead. “And I  _ still  _ get in trouble half as often as you do. It’s almost like you’re trying too hard or something! Put a shirt on, by the way,” he smirked. “You’re not impressing her.”

Briefly, before she could control it, she had a vivid memory of the low burn of Cinder’s fingernails across her belly. Mercury’s smirk widened enough to let her know that he’d read her reaction in her eyes, and her nails dug into her palms as she clenched her fists.

“And you think you are? I could find twelve of you just in Vale!”

“I think I don’t really care.” He waved a hand. “Don’t have to be special if you’re good. I mean, Cinder’s got to have  _ someone  _ around who actually knows their way around a real fight.”

Emerald forced herself not to flex her fingers. They wanted to inch toward her guns as if pulled by invisible wires, but she’d trained herself out of obvious tells years ago. And Cinder really  _ would  _ be furious if she shot Mercury.

“You mean someone to soak up punches,” she said through her teeth. “While  _ we  _ complete the actual mission.”

Mercury chuckled.

_ “We,” _ he mocked, sketching air quotes with his fingers.

Something in Emerald’s chest snapped. “Yeah,” she said. “Me and Cinder! I was here first, and we haven’t changed  _ anything  _ about how we run missions since you showed up! You’re just there! All the time! None of this works without me, the entire plan hinges on  _ my  _ Semblance, you’re--you’re just muscle!  _ I’m _ irreplaceable!”

_ “No one,” _ Cinder’s voice said coldly from the doorway, “is irreplaceable.”

* * *

“Cinder!”

Her name came out as a strangled gasp as Emerald whirled to face the doorway, heart pounding and ice water in her veins. She didn’t--she hadn’t--

Her mistress crossed to them slow and deliberate, heels clicking in the empty space, eyes never leaving Emerald. The strange, captivating flames dancing just behind those eyes weren’t playful now. They were like everything else about Cinder. Beautiful, unique, so precious you would risk your life to hold it in your hand for a moment--and waiting to consume you if you tried. The only thing worse than playing with fire was thinking yourself immune to it.

Maybe Emerald had just gone too long without being burned. 

(But she couldn’t help it, with Cinder even while fire licked at her skin she never felt she was warm enough, but the promise was always there--if she could just try a little harder, get a little bit closer, maybe the cold in her gut would fade for a moment, she couldn’t help  _ longing  _ for it...)

All her years of survival instinct screamed to run, to flinch back, defend herself. At least beg. But she wouldn’t do that. Not in front of Cinder. She  _ knew  _ her mistress hated infighting, she knew she’d disobeyed her orders by letting herself get distracted from the bigger picture, that starting a fight with Mercury on the eve of Cinder’s masterstroke could place the entire operation at risk over Emerald’s ego.

She could take it. She’d always taken Cinder’s punishments, her chastisements, without arguing or trying to get away. Shown that she really  _ could  _ submit to her judgement and authority. She knew her place, really she did, she just...she just forgot, sometimes…

It wasn’t enough to stop her from squeezing her eyes shut and tightening her shoulders as Cinder stepped within reach--but the hard Aura-enhanced slap she knew she’d earned never came.

After a moment of disorientation, Emerald dared to open her eyes, then blinked in bewilderment and turned around. Cinder had walked right past her, and just now was turning to face her, one hand idly running through Mercury’s hair.

“Emerald,” she purred. “Have you been fighting with your brother again?”

_ Ugh, _ Emerald thought reflexively.  _ Don’t call him that, he keeps trying to hit on me. _ An echo of a conversation from months ago, a lighter one. When the look Cinder gave her had been teasing, without dark anger running just under the surface.

“I’m...I’m sorry,” she said instead, off-balance. “It won’t happen…” No, Cinder could always tell when she was lying. “I’ll keep better control of myself next time. Ma’am.”

Cinder hummed, stroking the smirking Mercury’s hair one last time before taking a step toward Emerald. “Will you?”

She tried to pretend some of the tension didn’t leave her shoulders once Cinder stopped touching him.

“Yes, ma’am,” she said firmly, not a little desperately. “I promise, I can control myself. You know I can!”

“Hush.” Cinder circled her, fingertips brushing Emerald’s bangs off her face just for a moment. It was nothing like the lingering, affectionate caress she’d just given Mercury, and the difference burned. Cinder didn’t even look at her; just twitched two fingers over her shoulder and murmured, “Come.”

Mercury waved sarcastically, wiggling his fingers and mouthing  _ Have fun! _ Emerald didn’t even have a retort to mouth back at him. Her brain felt numb. She just turned and stumbled in Cinder’s wake.

They weren’t going all the way back to the Beacon dorms, since Mercury’s team was supposed to be en route to Mystral with him; that was a small mercy, at least. It was a short walk, really, just down a row of empty boxes in the locked storage room they were using as base and through a sealed connecting door to Cinder’s temporary...office? Bedroom? Her quarters, Emerald supposed.

A tap of Cinder’s scroll to the locking mechanism on the door sealed it again. The pneumatics sent out a hiss of cold air, and goosebumps prickled along Emerald’s arms. She stared into the dark room; she didn’t dare turn around.

There was a very long silence.

“Emerald.” Cinder’s voice was almost gentle. Sweet. Like honeyed wine in a poisoned cup. “What would I have done without you?”

That...wasn’t what she’d expected.

“I...I don’t--” she stammered. Cinder’s voice cut her off. Still calm, still sweet, but edged in steel this time.

“That was not a rhetorical question.”

Emerald forced herself to shut down her scattered thoughts. All right. All right. If Cinder hadn’t been there that day, or if Emerald had chosen a different mark…

She swallowed, fighting down the taste of bile. She never let herself think that. There was no point to what-ifs. Cinder  _ had  _ found her. She wasn’t going back. Cinder had found her, she had a place, as long as she stayed loyal and capable and kept earning the right to stand at Cinder’s right hand she was  _ safe  _ now.

But if she hadn’t been there.

“You...I don’t know! You would have found someone else, I guess?” She clenched and unclenched her fists even though it was a tell, because it was that or look over her shoulder to see what Cinder’s face looked like, and one of those things was as good as disobedience. “Or...come up with a different plan. One that didn’t need an illusionist. Whatever your plan was in the first place, ma’am.”

“Very good.” A few muted steps that still echoed, heels on bare metal until a single fingernail traced along the dip of Emerald’s spine. 

For all Mercury’s crude jokes, he wasn’t wrong about one thing, and Emerald would take  _ that  _ to her grave. Back before she’d cut her hair, Cinder had always loved to wind the tails around her wrist in order to grip the base. It gave her complete control of Emerald’s movements with barely any pain.

Cinder didn’t need to cause pain to get what she wanted.

Emerald had eventually changed the style, a decision that had  _ nothing  _ to do with months of watching her mistress’ fingers card through the  _ new acquisition’s _ short steel-grey hair. But she hadn’t quite been able to bring herself to get rid of those twin tails, and Cinder took advantage of them now. A gentle touch brought the trailing locks of hair together, and a slow twist wrapped them around her wrist once, then twice, then halfway again. She didn’t have to pull. The angle of Cinder’s hand changed slightly, and Emerald followed the motion onto her knees without thinking.

“I know,” Cinder murmured, “You would never mean to insinuate that my own success was dependent on your support. That would almost imply that I needed you more than the other way around. Wouldn’t it, Emerald?”

“No!” Emerald’s head snapped up, and a few hairs ripped themselves out at the roots, but with the sudden panic pulsing through her she barely noticed. “That’s not what I meant!”

“Shhh.” Gentle fingers ran through her hair, nails prickling against Emerald’s scalp but not scratching. It wasn’t affectionate, but it was  _ deliberate _ . Possessive. A claim-- _ mine. _ Emerald closed her eyes and shivered with sheer relief. “Of course it wasn’t. You need to be more careful with your words, Emerald. It would be terrible for us to have a misunderstanding.”

“Yes, ma’am,” Emerald breathed.

“Very good.” The warm fingers playing with her hair made one more pass before Cinder dropped her hold on Emerald’s hair and moved away. A tiny noise of protest escaped before Emerald could stop it; if Cinder noticed, she gave no indication.

Daring a peek from under her bangs, Emerald watched as Cinder crossed to a nearby stack of crates, perching on one of them as gracefully as if it were a throne as she expanded her scroll. Hesitantly, Emerald started to stand.

Cinder’s eyes flared in the dark. She didn’t say a word, but there was no humor in the tight line of her mouth and Emerald quickly lowered herself back to her knees, dropping her gaze respectfully. 

After a moment, she felt Cinder’s attention leave her. She held still and tried to ignore the way the hard floor dug into the studs on her chaps. This wasn’t the time to fidget. For a long time, the only sound in the echoey chamber was the occasional chirp of Cinder’s scroll.

With Cinder’s ever-present warmth so far away, Emerald realized for the first time how  _ cold  _ it was in here.

She didn’t know how much time had passed when Cinder finally spoke again.

“I’m curious.” Emerald risked glancing at her. She still hadn’t looked up from her scroll, but her mouth quirked on one side and there was a hint of the playful head-tilt that spelled either safety or imminent destruction, depending on Cinder’s mood. It meant: tread carefully, and don’t get cocky. She flicked her eyes over to meet Emerald’s, and the slight smirk widened just enough to be visible as she crossed her legs. “What  _ did  _ Mercury say to you?”

Emerald swallowed.

“Nothing, Cinder.”

“Emerald.”

Emerald was too familiar with that deceptively mild tone to mistake it for anything but the warning it was.

“He just…” It felt so stupid saying it out loud. Petty and unimportant. Like her, compared to her mistress. “It was stupid. He’s just...Mercury. I know better than to let him get to me. It won’t happen again. I won’t let it happen again.”

“You should know better,” Cinder agreed. “But that is  _ not  _ what I asked.”

Knowing she was out of chances now didn’t make Emerald’s throat close around the words any less.

“It was just...” Her hands balled into fists against her knees. “I  _ hate  _ it when he calls me that! He knows I hate it! I’ve got just as much right to be here as  _ he  _ does, I don’t know how he gets off on--” 

One look at Cinder’s face was enough to shut her up.

Shifting uncomfortably, she muttered “impulse purchase” at the floor.

Cinder’s peal of light, airy laughter wasn’t what Emerald had expected; there wasn’t enough mockery in it. She almost sounded  _ charmed. _

“Is that all?” Cinder’s smile widened as she slid her scroll closed and set it aside. She stood and approached her apprentice slowly, and Emerald dropped her gaze again. “He’s right.”

Emerald stopped breathing. She hadn’t even gotten a chance to process the shock, the razor pain of it--that was  _ cruel, _ even for Cinder, how  _ could  _ she--before Cinder’s hand was on her again, dragging through her hair.

“I hadn’t  _ dreamed  _ of finding such a gift,” she continued, a smile in her voice that was almost warm. She tugged lightly at Emerald’s hair, a cue to stand, and she obediently got to her feet. Cinder stepped closer, one hand toying with Emerald’s hair while the other rested reassuringly on her hip. “I could never have hinged my plans around it. There are very few who possess your abilities, and most of them have been...compromised.”

Huntsmen. Even the fallen ones had an irritating habit of retaining just enough honor that they would never have sworn themselves to Cinder. Not fully. Not the way Emerald had.

_ “You, _ on the other hand.” Emerald’s eyes drifted closed as Cinder let one long tail twirl around her finger. “You were a rare find, Emerald. I wanted you the moment I saw you.” A soft laugh against her ear. “So bold. So hungry. Oh, I  _ had  _ to have you.”

Cinder’s touch, the arm around her waist, drove any coherent thought from Emerald’s mind; but the words grounded her again, a gentle chastisement for forgetting what had truly caught her mistress’ attention in the first place. 

_ Emerald. What a lovely name. Are you hungry, Emerald? _

_ No.  _ A blatant lie.

Softly mocking laughter.  _ I think you are. And not just because you haven’t eaten since yesterday. I think you look around this city, and the hunger eats you alive. _

There had been no flames in her eyes back then, not yet. That was only the first step of what she’d needed Emerald for. But they’d still burned from within, still pinned her in place and seared away all of her defenses.

_ You’re hungry for justice. Revenge. Recognition for your skills and talents. Every day, you’re scorned by men and women who wouldn’t last a day in your circumstances, solely because  _ you  _ use your skills to survive, while  _ they  _ live comfortably thanks to nothing but sheer luck. If any of them had such an incredible gift, they would be revered, not spit at on the streets. You want to sink your teeth into them, Emerald. You want their blood. You want the respect you deserve. The power that should be your right. I know. I can see it in your eyes. _

_ You don’t know me, _ she’d wanted to say, but it had died in her throat because it was a lie. It felt like her soul was being laid bare. There was hunger in Cinder’s eyes, too, locked onto Emerald. Like she was going to devour her, and Emerald would let her. They were the same, in a way. No one would ever treat them like garbage again.

_ Why do you care what I want?  _ She’d asked instead. She’d wanted to snap, but it hadn’t come out angry.

Cinder had smiled, that slow mysterious smirk. She hadn’t answered, exactly.

_ You won’t get it. _ Soft. Almost kind.  _ This world doesn’t care about you, or your skills. You know that. None of  _ them  _ will ever respect you. They don’t see a clever young woman, a survivor with a powerful gift. And they never will. You’re a sneak thief and a street rat. A liar. No one will ever be foolish enough to give  _ you  _ anything of importance. That hunger will burn you up inside until one day, you slip up or snap. Die young and alone. And no one will ever even know your name. You’ll starve to death, Emerald. I think that would be a waste. _

_ Come with me,  _ she’d said, smiling gently as Emerald tried to pretend she wasn’t shaking, tried to pretend she hadn’t just flayed her alive and laid out everything that had ever caused her pain.  _ And you’ll  _ never  _ be hungry again. _

The words echoed every time Cinder held her still like this. Pinned against a wall, held in place by one wrist pulled behind her back, on one memorable occasion pressed into an actual bed. Cinder’s teeth at her throat were hungry in a way that almost scared her--made her feel like she could burn to ash and let Cinder’s fire consume her and still leave her unsatisfied.

But they set Emerald burning, too, and Cinder had been right; she hadn’t realized how painful the hollow ache in her chest was until Cinder first grabbed her by the chin while she was fleecing patrons in a crowded nightclub and took her in a blazing kiss and she felt  _ wanted, _ the gnawing hunger fading for a while.

“You’ve waited a long time for this, Emerald,” Cinder murmured. Sharp nails scratched along Emerald’s hips. “We both have. You want revenge. You want to watch the people who abandoned you stripped of everything they’ve so comfortably taken for granted all these years. You want to taste their fear at the destruction of their precious order.”

“Yes,” she breathed, and was rewarded for pressing back into Cinder’s grip with another low chuckle and warm lips teasing just behind her ear.  
  
“Then focus.” Any anger was long since gone from Cinder’s voice. Of course it was. No one understood better than her what dismissal and powerlessness did to a person. She’d always understood. “Prepare.” A cold smirk. “By tomorrow, you’ll have your fill. And I assure you, Emerald--I will  _ not  _ forget who made it possible.”


End file.
